<template>
  <div class="cart">
    <h4>全部商品</h4>
    <div class="cart-main">
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价（元）</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <div class="cart-body">
        <ul class="cart-list" v-for="good in cartList" :key="good.id">
          <li class="cart-list-con1">
            <input
              type="checkbox"
              name="chk_list"
              :checked="good.isChecked === 1"
              @input="singleChecked(good.skuId, good.isChecked === 1 ? 0 : 1)"
            />
          </li>
          <li class="cart-list-con2">
            <img :src="good.imgUrl" />
            <div class="item-msg">
              {{ good.skuName }}
            </div>
          </li>
          <li class="cart-list-con3">
            <div class="item-txt">相机升级款</div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{ good.skuPrice }}</span>
          </li>
          <li class="cart-list-con5">
            <a
              href="javascript:void(0)"
              class="mins"
              @click="changeNum(good, -1)"
              >-</a
            >
            <input
              autocomplete="off"
              type="text"
              :value="good.skuNum"
              minnum="1"
              class="itxt"
              @change="changeTextNum(good, $event)"
            />
            <a
              href="javascript:void(0)"
              class="plus"
              @click="changeNum(good, 1)"
              >+</a
            >
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{ good.skuPrice * good.skuNum }}</span>
          </li>
          <li class="cart-list-con7">
            <a class="sindelet" @click="deleteSingle(good.skuId)">删除</a>
            <br />
            <a href="#none">移到收藏</a>
          </li>
        </ul>
      </div>
    </div>
    <div class="cart-tool">
      <div class="select-all">
        <input class="chooseAll" type="checkbox" v-model="allChecked" />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="deleteAll">删除选中的商品</a>
        <a href="#none">移到我的关注</a>
        <a href="#none">清除下柜商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">
          已选择 <span>{{ allNum }}</span
          >件商品
        </div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{ allPrice }}</i>
        </div>
        <div class="sumbtn">
          <router-link to="/trade">结算</router-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import {
  reqCartList,
  reqCartSingleChange,
  reqCartAllChange,
  reqCartSingleDelete,
  reqCartAllDelete,
  reqAddOrUpdateCart,
} from "@/api";
export default {
  name: "ShopCart",
  data() {
    return {
      cartList: [],
    };
  },

  mounted() {
    this.getCartList();
  },

  methods: {
    //1.获取购物车列表
    async getCartList() {
      const result = await reqCartList();

      //给每一个商品都添加一个属性：isReq。作为“开关”
      this.cartList =
        result[0]?.cartInfoList.map((item) => {
          item.isReq = false;
          return item;
        }) || [];
    },

    //2.修改单个数据的选中状态
    async singleChecked(skuId, isChecked) {
      //发送请求切换
      await reqCartSingleChange(skuId, isChecked);
      //重新发送请求
      this.getCartList();
    },

    //3.删除单个商品
    async deleteSingle(skuId) {
      //发送删除请求
      await reqCartSingleDelete(skuId);

      //重新发送请求
      this.getCartList();
    },

    //4.删除已经选中的所有商品
    async deleteAll() {
      const skuIdList = this.cartList.reduce(
        (p, c) => (c.isChecked === 1 ? [...p, c.skuId] : p),
        []
      );

      await reqCartAllDelete(skuIdList);

      //重新发送请求
      this.getCartList();
    },

    //5.通过按钮改变购物车中商品的数量
    async changeNum(good, num) {
      //如果正在发送请求，则直接return，不再操作
      //作用是节流，如果isReq的值是true，则直接return
      if (good.isReq) return;

      //当进行到这一步的时候，说明了两点：一、现在暂时还没有请求。二、马上要开始请求了
      //所以我们改变开关isReq的值
      good.isReq = true;

      //判断如果是减少数量的话,则判断临界值
      if (num === -1 && good.skuNum <= 1) return (good.isReq = false);

      //发送修改数量请求
      await reqAddOrUpdateCart(good.skuId, num);

      //重新发送请求
      await this.getCartList();

      //在最后重新改变isReq的值
      good.isReq = false;
    },

    //6.在直接修改购物车商品数量的时候，处理输入值的函数
    async changeTextNum(good, e) {
      //获取用户输入的值，把这个值转化为数字
      const userInputNum = parseInt(e.target.value);
      e.target.value = userInputNum;

      //判断输入的值是否是正确的数字，如果这个值有问题则变为原始值，并且return
      if (isNaN(userInputNum) || userInputNum < 1) {
        e.target.value = good.skuNum;
        return;
      }

      //这个项目后台程序写的偷懒，从逻辑上判断需要这一步来修正值
      await reqAddOrUpdateCart(good.skuId, userInputNum - good.skuNum);

      //重新请求数据
      await this.getCartList();
    },
  },

  computed: {
    //总数量
    allNum() {
      return this.cartList.reduce((p, c) => p + c.skuNum, 0);
    },

    //总价格
    allPrice() {
      return this.cartList.reduce((p, c) => p + c.skuNum * c.skuPrice, 0);
    },

    //商品的全选状态
    allChecked: {
      get() {
        return this.cartList.every((item) => item.isChecked === 1);
      },
      async set(value) {
        //获取所有商品的skuId组成的数组
        const skuIdList = this.cartList.map((item) => item.skuId);
        await reqCartAllChange(value ? 1 : 0, skuIdList);

        //重新发送请求
        this.getCartList();
      },
    },
  },
};
</script>

<style lang="less" scoped>
.cart {
  width: 1200px;
  margin: 0 auto;

  h4 {
    margin: 9px 0;
    font-size: 14px;
    line-height: 21px;
  }

  .cart-main {
    .cart-th {
      background: #f5f5f5;
      border: 1px solid #ddd;
      padding: 10px;
      overflow: hidden;

      & > div {
        float: left;
      }

      .cart-th1 {
        width: 25%;

        input {
          vertical-align: middle;
        }

        span {
          vertical-align: middle;
        }
      }

      .cart-th2 {
        width: 25%;
      }

      .cart-th3,
      .cart-th4,
      .cart-th5,
      .cart-th6 {
        width: 12.5%;
      }
    }

    .cart-body {
      margin: 15px 0;
      border: 1px solid #ddd;

      .cart-list {
        padding: 10px;
        border-bottom: 1px solid #ddd;
        overflow: hidden;

        & > li {
          float: left;
        }

        .cart-list-con1 {
          width: 4.1667%;
        }

        .cart-list-con2 {
          width: 25%;

          img {
            width: 82px;
            height: 82px;
            float: left;
          }

          .item-msg {
            float: left;
            width: 150px;
            margin: 0 10px;
            line-height: 18px;
          }
        }

        .cart-list-con3 {
          width: 20.8333%;

          .item-txt {
            text-align: center;
          }
        }

        .cart-list-con4 {
          width: 12.5%;
        }

        .cart-list-con5 {
          width: 12.5%;

          .mins {
            border: 1px solid #ddd;
            border-right: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }

          input {
            border: 1px solid #ddd;
            width: 40px;
            height: 33px;
            float: left;
            text-align: center;
            font-size: 14px;
          }

          .plus {
            border: 1px solid #ddd;
            border-left: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
          }
        }

        .cart-list-con6 {
          width: 12.5%;

          .sum {
            font-size: 16px;
          }
        }

        .cart-list-con7 {
          width: 12.5%;

          a {
            color: #666;
          }
        }
      }
    }
  }

  .cart-tool {
    overflow: hidden;
    border: 1px solid #ddd;

    .select-all {
      padding: 10px;
      overflow: hidden;
      float: left;

      span {
        vertical-align: middle;
      }

      input {
        vertical-align: middle;
      }
    }

    .option {
      padding: 10px;
      overflow: hidden;
      float: left;

      a {
        float: left;
        padding: 0 10px;
        color: #666;
      }
    }

    .money-box {
      float: right;

      .chosed {
        line-height: 26px;
        float: left;
        padding: 0 10px;
      }

      .sumprice {
        width: 200px;
        line-height: 22px;
        float: left;
        padding: 0 10px;

        .summoney {
          color: #c81623;
          font-size: 16px;
        }
      }

      .sumbtn {
        float: right;

        a {
          display: block;
          position: relative;
          width: 96px;
          height: 52px;
          line-height: 52px;
          color: #fff;
          text-align: center;
          font-size: 18px;
          font-family: "Microsoft YaHei";
          background: #e1251b;
          overflow: hidden;
        }
      }
    }
  }
}
</style>
